Electrode for microelectromechanical system microphone

Abstract

The invention relates to a bifurcated electrode for a micro-electro-mechanical system (MEMS) microphone. In one embodiment, a MEMS sensor includes a membrane, a membrane electrode formed in a portion of the membrane, and a backplate positioned parallel to the membrane and separated by a gap. The backplane includes a first region of the backplane, where the first region of the backplane has a plurality of first perforations of a first density, the backplane electrode is formed in a portion of the first region of the backplane, and a portion of the membrane electrode overlaps a portion of the backplane electrode in a sensing region where the sensing capacitor is formed, the sensing capacitor is configured to sense movement of the membrane in response to acoustic pressure. The backsheet further includes a second region of the backsheet having a plurality of second perforations of a second density, where the second density is greater than the first density.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to U.S. Non - Provisional Patent Application No. 18 / 448,601, filed on August 11, 2023, entitled "ELECTRODES FOR MICROELECTROMECHANICAL SYSTEM MICROPHONES", U.S. Provisional Patent Application No. 63 / 384,791, filed on November 23, 2022, entitled "SPLITELECTRODES FOR MICROPHONES", and U.S. Provisional Patent Application No. 63 / 507,218, filed on June 9, 2023, entitled "SPLIT ELECTRODES FOR MICROPHONES", the entire disclosures of which are incorporated herein by reference. Technical Field

[0003] The subject disclosure generally relates to microelectromechanical systems (MEMS) devices, and more particularly, to MEMS microphones. Background Art

[0004] MEMS microphones typically have a diaphragm that forms a variable capacitor with a underlying backplate. An audible signal is received to cause the diaphragm to vibrate, thereby generating a variable capacitance signal representative of the audible signal. Such a variable capacitance signal can be amplified, recorded, or otherwise transmitted to another electronic device.

[0005] There are three sources of noise in MEMS microphones, namely, application - specific integrated circuit (ASIC), MEMS, and packaging. Noise caused by one or more of these sources may degrade the quality of the variable capacitance signal described above, e.g., in terms of signal - to - noise ratio (SNR) and / or other metrics. The diaphragm of a MEMS microphone is typically configured as a membrane composed of one or more layers, and the damping between this membrane and the backplate may be a cause of MEMS noise. Accordingly, it is desirable to implement techniques in MEMS microphones to improve MEMS SNR and / or reduce noise caused by MEMS and / or other sources. Brief Description of the Drawings

[0006] The non - limiting embodiments of the subject disclosure are described with reference to the following drawings, wherein, unless otherwise specified, like reference numerals refer to like components in the various views:

[0007] Figure 1AIs a cross-sectional view depicting the response to sound pressure in an exemplary MEMS microphone or acoustic sensor as described herein.

[0008] Figure 1B Is a simplified top-down perspective view depicting a MEMS acoustic sensor configured according to various embodiments of the present disclosure.

[0009] Figure 2A Is a block diagram depicting an example sensing circuit of a MEMS acoustic sensor.

[0010] Figure 2B Is a circuit diagram depicting an example sensing circuit of a MEMS acoustic sensor.

[0011] Figure 3 Is a simplified side perspective view depicting the MEMS acoustic sensor shown in FIG. 1.

[0012] Figure 4 Is a simplified top-down perspective view depicting a MEMS acoustic sensor configured according to various embodiments of the present disclosure.

[0013] Figure 5A Is a cross-sectional view depicting the response to sound pressure in an exemplary MEMS microphone or acoustic sensor as described herein.

[0014] Figure 5B Is according to Figure 5A A simplified top-down perspective view of a MEMS acoustic sensor configured according to the embodiment shown.

[0015] Figures 6 to 8 Is a simplified top-down perspective view depicting individual MEMS acoustic sensors configured according to various embodiments of the present disclosure.

[0016] Figures 9 to 10 Is a diagram depicting non-limiting aspects associated with the exemplary MEMS acoustic sensor or microphone backplane described herein.

[0017] Figures 11 to 14 Is an additional simplified top-down perspective view depicting individual MEMS acoustic sensors configured according to various embodiments of the present disclosure.

[0018] Figure 15 Is a simplified top-down perspective view depicting a MEMS acoustic sensor including a shielding electrode configured according to various embodiments of the present disclosure.

[0019] Figure 16 Is a top-down perspective view depicting an exemplary MEMS microphone membrane and backplane configured according to various embodiments of the present disclosure.

[0020] Figure 17Is an isometric view depicting an example MEMS microphone diaphragm and backplate configured according to various embodiments of the present disclosure. Detailed Description

[0021] One or more aspects of the present disclosure generally relate to MEMS microphones and their components, such as diaphragms and / or backplates. By employing various implementations as described herein, the performance of MEMS microphones can be improved in terms of signal quality measured by signal-to-noise ratio (SNR) and / or other metrics by reducing the amount of noise contributed by the MEMS acoustic sensors associated with the microphones.

[0022] As used herein, a microelectromechanical (MEMS) system can refer to any of a variety of structures or devices fabricated using semiconductor-like processes and exhibiting mechanical characteristics, such as the ability to move or deform. For example, such structures or devices can interact with electrical signals. As a non-limiting example, a MEMS acoustic sensor can include a MEMS transducer and an electrical interface. Additionally, MEMS structures or devices can include, but are not limited to, gyroscopes, accelerometers, magnetometers, environmental sensors, pressure sensors, acoustic sensors or microphones, and radio frequency components.

[0023] In one aspect disclosed herein, a MEMS sensor, such as a MEMS acoustic sensor, includes a diaphragm, a diaphragm electrode formed in a portion of the diaphragm, and a backplate positioned parallel to the diaphragm and separated from the diaphragm by a gap. The backplate includes a first region of the backplate, where a first density of a plurality of first through-holes are formed in the first region, a backplate electrode is formed in a portion of the first region, and a portion of the diaphragm electrode overlaps a portion of the backplate electrode in a sensing region forming a sensing capacitor. The sensing capacitor is configured to sense the movement of the diaphragm in response to sound pressure. The backplate further includes a second region of the backplate, where a second density of a plurality of second through-holes are formed in the second region, and the second density is greater than the first density.

[0024] In another aspect disclosed herein, a MEMS sensor, such as a MEMS acoustic sensor, includes a diaphragm, a diaphragm electrode formed in a portion of the diaphragm, a backplate positioned parallel to the diaphragm and separated from the diaphragm by a gap, and a backplate electrode formed in a portion of the backplate. The diaphragm electrode at least partially overlaps the backplate electrode in a sensing region forming a sensing capacitor. The MEMS sensor further includes a sensing circuit coupled to the sensing capacitor and configured to sense the movement of the diaphragm in response to sound pressure. Additionally, the sensing region is located away from the point of maximum movement of the diaphragm in response to sound pressure.

[0025] In another aspect disclosed herein, a MEMS acoustic sensor includes a membrane, a membrane electrode formed in a portion of the membrane, and a backplate positioned parallel to the membrane and separated by a gap. The backplate includes a first region of the backplate having a plurality of first perforations with a first density, a second region of the backplate having a plurality of second perforations with a second density, and a backplate electrode formed in a portion of the backplate, the second density being greater than the first density. A portion of the membrane electrode overlaps a portion of the backplate electrode in a sensing region forming a sensing capacitor, and the sensing capacitor is configured to sense movement of the membrane in response to an acoustic pressure. The first region of the backplate surrounds a point of maximum movement of the membrane in response to the acoustic pressure, and the second region of the backplate is remote from the point of maximum movement of the membrane in response to the acoustic pressure.

[0026] Other embodiments and various examples, scenarios, and implementations will be described in more detail below. The following description and the drawings set forth certain illustrative embodiments of the specification. However, these embodiments merely indicate some of the various ways in which the principles of the specification may be employed. Other advantages and novel features of the described embodiments will become apparent from the following description when considered in conjunction with the drawings.

[0027] Referring now to the drawings, various views of an exemplary MEMS microphone assembly are provided. It should be noted that the drawings are not drawn to scale, either within a single figure or between different figures.

[0028] Figure 1A is a simplified cross-section of an exemplary MEMS acoustic sensor 100, which shows the response to an acoustic pressure in a MEMS microphone. As Figure 1A shown, the sensor 100 may include a membrane 10 that bends in response to an air pressure, e.g., an air pressure generated by an acoustic signal, represented as an input pressure in Figure 1A . The area of the membrane 10 is represented as A in Figure 1A . The membrane 10 is separated from the backplate 30 by a gap. The sensor 100 shown in m includes two backplate electrodes 20, where each electrode has a total area of 1 / 2A Figure 1A , where Ac is the total electrode area associated with the sensor 100. The backplate electrodes 20 formed on the backplate 30 and the membrane electrode (not shown in c Figure 1A ) formed on the membrane 10 form a variable capacitor C MEMS , which exhibits a capacitance change depending on the deflection amount of the membrane 10. Then, the acoustic signal can be captured by measuring the capacitance change generated at each of the backplate electrodes 20. The region of the sensor 100 located between the membrane 10 and the housing of the sensor in which the backplate 30 is positioned is referred to as the back volume of the sensor 100, and the back volume pressure of the sensor 100 is represented as P BV .​

[0029] Since the bending of the membrane 10 causes air displacement within the sensor 100, the backplate 30 can be perforated to allow air to pass through the backplate. However, despite the perforations, the backplate 30 still blocks such passage of air. This resistance, in turn, generates noise. There are currently techniques for reducing MEMS noise caused by air resistance through the backplate, but each of these techniques has associated drawbacks. For example, the MEMS SNR can be increased by increasing the MEMS area (e.g., the area of the membrane and the backplate), but increasing the MEMS area results in an increase in the size of the microphone chip and an increase in production costs. As another example, the hole pitch in the backplate can be reduced to allow a greater air flow through the backplate, but this may reduce the signal generated by the sensor and also compromise the mechanical strength of the backplate. As a further example, a vacuum can be formed between the membrane and the backplate, but doing so significantly increases the complexity of the sensor, e.g., due to the need for additional mechanical components to connect the membrane and the backplate in the presence of a vacuum, and also the process complexity of manufacturing the sensor and its associated costs.

[0030] To further achieve the above and / or related objectives, various embodiments described herein can reduce the damping, air resistance, and / or the effects of other masses of the MEMS sensor backplate to reduce noise associated with the backplate and increase the device SNR. In some embodiments, a multi-region backplate can be used, where the respective regions of the backplate have different perforation patterns, which can reduce the overall resistance of the backplate. In one example, a first region of the backplate can have a first number of holes or perforations of a first size or density, and a second (different) region of the backplate can have a second (different) number of holes or perforations of a second (different) size or density. In another example, the backplate can be significantly smaller than its corresponding membrane, e.g., such that openings are formed between the respective areas of the backplate.

[0031] In other embodiments provided herein, the sensing electrodes of the MEMS sensor are positioned away from the point of maximum movement of the membrane, e.g., the center of the membrane. Among other advantages, offset sensing electrodes used in this manner can reduce the damping between the membrane and the backplate relative to similar devices that use electrodes located at the center.

[0032] Although various examples related to MEMS acoustic sensors and associated microphones are described herein, it should be noted that concepts similar to those described herein can also be applied to other types of sensors or devices. For example, structures similar to those described herein can be used to improve the performance of capacitive pressure sensors, capacitive micromachined ultrasonic transducers (CMUTs), and / or any other capacitive MEMS sensor devices. It should be noted that unless otherwise explicitly stated, the specification and the claimed subject matter are not intended to be limited to any particular type of sensor.

[0033] Now referring to Figure 1B , a simplified top perspective view of a MEMS sensor 100B is presented, e.g., a MEMS acoustic sensor configured according to various embodiments of the present disclosure. It should be noted that techniques similar to those described herein can be applied to MEMS sensors of other shapes, such as polygons (e.g., hexagons, octagons, etc.), circles, or ellipses, and / or other suitable shapes. Various examples of circular MEMS sensors are described below with reference to Figures 11 to 15 .

[0034] Figure 1B The MEMS sensor 100B shown in Figure 1A includes a membrane 10, which can be composed of any material suitable for achieving the flexibility of the membrane 10. As shown, the membrane 10 can be clamped, anchored, and / or otherwise attached to one or more sides of the perimeter of the MEMS sensor 100B. In this embodiment, the membrane 10 is attached to the short edges of the sensor 100B, i.e., the left and right edges as shown in Figure 1B . Although for illustrative purposes the membrane 10 is shown as being offset from the short edges of the sensor 100B, it should be noted that in some embodiments, the membrane 10 can span the entire length of the sensor 100B. It should be noted that in Figure 1B and subsequent figures, for simplicity of illustration, the membrane 10 is shown as transparent.

[0035] As further shown in Figure 1B , respective electrodes can be formed as respective portions of the membrane 10, e.g., portions corresponding to the sensing region 110. For clarity, the electrodes formed in the membrane 10 are referred to herein as membrane electrodes. As further shown in Figure 1B , the MEMS sensor can include a backplate 30, which is positioned parallel to the membrane 10, e.g., such that the membrane 10 is located above the backplate 30 with respect to the view shown in Figure 1B , and the view extends in an out-of-page direction from the view shown in Figure 1B . Additionally, the membrane 10 can be separated from the backplate 30 by a gap to facilitate capacitive sensing, as will be described below.

[0036] In some embodiments, the backplate 30 may be attached or connected orthogonally to the connection of the membrane to the perimeter of the sensor 100B (e.g., associated with the sensor housing). Thus, in Figure 1B the example shown, the membrane 10 may be anchored to the short sides of the perimeter of the sensor 100B, and the backplate 30 may be attached to the two long sides of the perimeter of the sensor 100B. Other techniques may also be used.

[0037] Figure 1B The backplate 30 shown in Figure 1B may be perforated to include holes or openings in the backplate 30, as shown by the pattern of the backplate 30 in Figure 1B While the backplate 30 shown in Figure 1B has several perforations of a single density (size), other embodiments may include a backplate with different regions of different perforation densities, or a discontinuous backplate that is substantially smaller than the membrane, which will be described in further detail below.

[0038] Figure 1B The backplate 30 shown in Figure 1B may include respective electrodes formed in a portion of the backplate 30, namely, the backplate electrodes 20. The backplate electrodes 20 may at least partially overlap the above-described membrane electrodes in respective sensing regions 110. As a result, the sensing regions 110 form sensing capacitors, which may be configured to sense the movement of the membrane 10 in response to sound pressure. A voltage difference is applied between the sensing electrodes and the backplate electrodes in order to sense the movement of the membrane due to sound pressure.

[0039] The movement of the membrane 10 causes a change in the gap between the membrane electrodes and the backplate 30, thereby causing a change in the capacitance between the membrane electrodes and the backplate 30. As used herein, the sensing region 110 refers to the overlapping region between the membrane electrodes and the backplate or between the membrane and the backplate electrodes. The sensing regions 110 are electrically coupled to the sensing circuit via a connector 25. The connector 25 may be implemented, for example, by a routing region that includes the overlapping area of the backplate electrodes and the membrane electrodes, thereby forming a routing capacitor. The routing capacitor may be configured such that the capacitance of the routing capacitor responds less to changes in sound pressure than the capacitance of the sensing capacitor responds to corresponding changes in sound pressure.

[0040] As Figure 1B is further shown in Figure 1B the sensing regions 110 are located at positions away from the point of maximum movement of the membrane in response to sound pressure, e.g., the center of the membrane 10. As a result, the signal generated by the deflection of the membrane and the amount of noise generated by the acoustic resistance of the backplate 30 are reduced. The reduction in noise is greater than the reduction in signal, thereby resulting in a better signal-to-noise ratio.

[0041] In Figure 1BIn the example shown, the respective sensing regions 110 are symmetrically offset relative to the center of the membrane 10, which may cause the signal captured by the sensor to be approximately doubled relative to the signal that would be captured by a single sensing region 110. For example, this can be used to compensate for the reduced sensitivity associated with placing the sensing regions 110 in an area that excludes the maximum motion point of the membrane 10. Figure 1B The sensitivity of the sensor shown in can also be increased by increasing the compliance of the membrane 10, for example, by reducing the tension force on the membrane 10. Other techniques for increasing sensitivity can also be used, such as reducing the size of the gap between the membrane 10 and the backplane 30, applying an additional voltage difference between the backplane 20 and the membrane 10, and / or other techniques.

[0042] Figure 2A A block diagram of a MEMS acoustic sensor is shown, which is an acoustic sensor implemented by a MEMS device 200 here. The acoustic sensor includes a capacitive sensing element 210, and the capacitive sensing element 210 can capacitively sense the sound pressure applied to the MEMS device 200. In one embodiment, the capacitive sensing element 210 can be implemented via electrodes formed in one of the membrane or the backplane associated with the MEMS device 200, which overlaps with the other of the membrane and the backplane. For example, at the sensing region 110 described above regarding Figure 1B The capacitive sensing element 210 is electrically coupled to a capacitive sensing circuit 220, and the capacitive sensing circuit 220 can generate an output signal representing the sound pressure applied to the capacitive sensing element 210.

[0043] Figure 2B An example implementation of the capacitive sensing circuit 220 is shown, which can measure the change in the MEMS capacitance 23 (C MEMS ) caused by the change in sound pressure. A bias voltage V b is applied to the sensing circuit 220, and the sensing circuit 220 feeds power to a bias resistor 27 and a sensing element 23 including a backplane electrode 20 and a membrane electrode 10 26. In some embodiments, the sensing element 23 is electrically coupled to a high-pass filter (HPF) 28, and the high-pass filter 28 includes an HPF resistor (R HPF ) and an HPF capacitor (C HPF ). Figure 2B The HPF 28 shown in is electrically coupled to a unity-gain buffer 29, and the unity-gain buffer 29 generates an output signal (V o ) of the capacitive sensing circuit 220 in response to the sound pressure.

[0044] Now turning to Figure 3 , depicts Figure 1BSimplified side perspective view of the MEMS sensor 100B shown in. As Figure 3 shown, the membrane 10 and the backplate 30 are separated by a gap 40, forming a variable capacitor that exhibits a capacitance related to the amount of acoustic pressure applied to the membrane 10. The sensing region 110 is formed by the overlap of the electrodes in the membrane 10 and the backplate 30. In Figure 3 , the electrode formed on the membrane is denoted by 22. The capacitance of the sensing region 110 can be measured, which corresponds to the overlap between the membrane electrode 22 and the electrode formed in the backplate 30, to obtain an acoustic signal. Although the sensing region 110 shown in Figure 3 is separated from the membrane 10 and the backplate 30, it should be noted that the sensing region 110 can be implemented by the electrodes formed in the membrane 10 and the backplate 30 respectively. In other embodiments, the electrodes can be formed on the membrane or the backplate.

[0045] Figure 4 Another exemplary rectangular MEMS sensor 400 having a membrane 10 and a backplate 30 is shown, which can be positioned in a manner similar to that of the sensor 100B shown in Figure 1B . Similar to the sensor 100B shown in Figure 1B , Figure 4 the membrane 10 and the backplate 30 of the sensor 400 shown in can be positioned parallel to each other and separated by a gap 40, for example, as shown in Figure 3 . Additionally, similar to the sensor 100B shown in Figure 1B , the sensing region 110 can have a split electrode configuration having one or more membrane / backplate electrodes, here two membrane / backplate electrodes, formed in the portion of the membrane 10 corresponding to the sensing region 110. The membrane 10 can also be anchored, clamped, and / or otherwise attached along both sides of the membrane 10 in a manner similar to that of the sensor 100B shown in Figure 1B . Furthermore, the sensing region 110 can be electrically coupled to the sensing circuit via a connector 25 in a manner similar to that of the sensor 100B in Figure 1B .

[0046] As Figure 4 further shown, the backplate 30 of the sensor 400 can include multiple regions, here two first regions 32 and one second region 34. Figure 4The first region 32 of the backplate 30 shown in [Fig.] is located on either side of the sensor 400, i.e., adjacent to the respective edges of the membrane 10, and may have a number of holes or perforations of a first size or density. The second region 34 of the backplate 30 is located at a position corresponding to the maximum deflection point of the membrane 10, i.e., at the center of the backplate 30, and may have a number of holes or perforations of a second size or density, the second size or density being greater than the first size or density. In other words, the first region 32 of the backplate 30 may be referred to as a low hole density region, where the "density" used in this way is defined as the total area of the perforations in the region divided by the total area of the region, and the second region 34 of the backplate 30 may be referred to as a high hole density region. By using a higher hole density in the second region 34 of the backplate 30 compared to the first region 32 where the sensing region 110 of the backplate 30 is located, for example, due to the increased airflow through the backplate 30 at the first region 32, the damping between the membrane 10 and the backplate 30 can be reduced at the first region 32 of the backplate 30.

[0047] In a manner similar to Figure 1B the sensor 100B shown in [Fig.], the backplate electrodes may be formed as part of the first region 32 of the backplate 30, e.g., corresponding to the sensing region 110, which may form a sensing capacitor configured to sense the movement of the membrane 10 in response to sound pressure. Although in Figure 4 the example shown in [Fig.], the first regions 32 of the backplate 30 and their corresponding backplate electrodes are symmetrically offset from the center of the membrane, e.g., in a manner similar to the backplate electrodes shown in Figure 1B [Fig.], it should be noted that the first regions 32 and / or their corresponding electrodes may be positioned within the sensor in any suitable manner.

[0048] In some embodiments, additional electrodes (referred to herein as shield electrodes 60) may be formed in the second region 34 of the backplate 30, or in a portion of the membrane 10 adjacent to the first region 34 of the backplate 30, and are electrically coupled to the circuit via a connector 24 connected to the membrane 10 in order to reduce the electrostatic force acting on the membrane, and thus reduce the deflection of the membrane 10. The shield electrodes 60 are described in further detail below with respect to Figure 15 [Fig.].

[0049] Figure 5A A cross-section of another example MEMS sensor 500 with a bifurcated electrode configuration is shown, while Figure 5B a top view is shown, and the bifurcated electrode configuration includes a membrane 10 similar to the membrane 10 shown in Figure 4 [Fig.]. Contrary to the multi-region backplate of the sensor 400 shown in Figure 4 [Fig.], the high-density perforation region of the backplate is removed, e.g., such that at the center of the sensor 500 and / orFigures 5A to 5B There is a single opening along the side of the sensor 500 in the manner shown, resulting in two different backplates 30. In the example shown in FIG. 5, the entire backplate 30 or substantially all of the backplates 30 can be associated with the backplate electrodes such that the sensing area 110 of the sensor 500 occupies all or substantially all of the area of the backplate 30. In various embodiments, Figure 5B the backplate shown in can be used to further reduce the damping between the membrane 10 and the backplate 30, while Figure 4 the multi-region backplate shown in can be used to increase the mechanical robustness of the sensor 400, for example, in the case of overvoltage.

[0050] Next, referring to Figure 6 , an example rectangular MEMS sensor 600 is shown, which includes a membrane 10 that can be configured according to the various embodiments described above. The sensor 600 also includes a backplate 30 having a first region 32 and two second regions 34, which, for example, can include low-density perforations and high-density perforations, respectively, and they are similar to those described above with respect to Figure 4 . Here, the membrane electrodes are formed in the membrane 10 at an area corresponding to the center of the membrane 10, and the backplate electrodes can be formed in the first region 32 of the backplate 30. As shown in Figure 6 , the backplate electrodes can extend from the first region 32 of the backplate 30 into a part of the second region 34 of the backplate 30, thereby generating a sensing area 110 that extends beyond the perimeter of the first region 32 of the backplate 30. The sensing area 110 can be electrically coupled to the sensing circuit via the connector 25 in a manner similar to that of the sensor 100B in Figure 1B .

[0051] Now turning to Figure 7 , another example rectangular MEMS sensor 700 is shown, which includes a membrane 10 that can be configured according to the various embodiments described above. Relative to the sensor 500 shown in Figure 5B , the first region 32 of the backplate 30 of the sensor 700 shown in Figure 7 is positioned closer to the center of the membrane 10, and the additional second regions 34 of the backplate 30 can be positioned at the respective edges of the sensor 700. As an alternative to the sensor 700 shown in Figure 7 , one or more of the second regions 34 of the backplate 30 can be replaced by a single large hole or opening, for example, in a manner similar to that shown in Figure 5B .

[0052] Figure 8 Another example rectangular MEMS sensor 800 is shown, which can include a membrane 10 and a backplate 30 having the same as Figure 7The first region 32 and the second region 34 shown are similar to the first region 32 and the second region 34. In addition, Figure 8 The sensor 800 shown also includes a section of the peripheral holes 50 along the periphery (perimeter) of the backplate 30. The peripheral holes 50 may be smaller than the backplate holes associated with the first region 32 and the second region 34 of the backplate 30 and may be positioned along the perimeter of the backplate 30 to improve the stress distribution along its edges.

[0053] Figures 9 to 10 A non-limiting example pattern of the peripheral holes 50 that can be used in the sensor 800 is depicted. First referring to Figure 9 , a non-limiting aspect associated with an exemplary MEMS acoustic sensor or microphone backplate 900 is depicted. Figure 9 FIG. shows a partitioning of an exemplary MEMS backplate structure where the backplate 900 has a central region 910, an edge region 920, and a transition region 930. The central region 910 is characterized by a uniform size and distribution of larger central holes towards the center of the MEMS acoustic sensor or microphone backplate 900. The edge region 920 is characterized by a uniform size and distribution of edge pattern (peripheral) holes 940 in the rod-like or capsule-shaped profile of the MEMS acoustic sensor or microphone backplate 900, and the transition region 930 is characterized by an irregular size and distribution of transition holes between the edge region 920 and the central region 910.

[0054] Figure 10 FIG. shows a non-limiting aspect associated with another exemplary MEMS acoustic sensor or microphone backplate 1000 described herein. Figure 9 FIG. shows a partitioning of an exemplary MEMS backplate structure where the MEMS acoustic sensor or microphone backplate 1000 includes a central region 910, an edge region 920, and a transition region 930, which may be arranged in a manner similar to that described above with respect to Figure 9 . Here, the edge region 920 is characterized by a uniform size and distribution of edge pattern (peripheral) holes 1010 in the droplet-shaped profile for the MEMS acoustic sensor or microphone backplate 1000.

[0055] Next referring to Figures 11 to 15 , various examples of generally circular MEMS sensors, such as MEMS acoustic sensors, are shown. Although Figures 11 to 15 shows examples of circular sensors, it should be noted that concepts similar to those described below with respect to Figures 11 to 15 can also be applied to sensors of any shape having a clamped / anchored periphery, such as oval sensors and / or sensors of any other suitable shape (e.g., square, rectangular, hexagonal, octagonal, etc.).

[0056] Referring now to Figure 11 , an exemplary circular MEMS sensor 1100 configured in accordance with various embodiments of the present disclosure is shown, such as a MEMS acoustic sensor. As described above, although Figure 11 a circular sensor 1100 is shown, concepts similar to those shown in Figure 11 can be used for an elliptical sensor, e.g., by utilizing different major and minor axes, and / or any other shape having an anchored edge. In Figure 11 and the subsequent figures, the membrane edge is denoted by 11. Figure 11 The sensor 1100 shown in Figure 11 includes a membrane 10, which may be composed of materials similar to those of the exemplary rectangular sensors described above, and / or manufactured using similar processes. Here, the membrane 10 has the same shape as the sensor 1100, e.g., circular (or elliptical), and may be attached to the sensor 1100 at least around the perimeter of the sensor 1100. Although for illustrative purposes, the membrane 10 is shown in Figure 11 as being disposed from the edge of the sensor 1100, it should be noted that in some embodiments, the membrane 10 may extend completely to the edge of the sensor 1100. Additionally, it should be noted that Figure 11 the membrane 10 shown in Figures 12 to 15 and the membrane 10 shown in Figures 12 to 15 which will be described in further detail below, are illustrated as transparent for purposes of clarity of illustration, in a manner similar to the above-described rectangular sensors.

[0057] As Figure 11 further shown, the sensor 1100 includes a backplate 30, which has the same shape as the sensor 1100 and the membrane 10. Here, the backplate 30 includes a single region spanning the entire sensor 1100. A multi-region backplate may also be used, which will be described in further detail below. Figure 11 The sensor 1100 shown in Figure 11 also includes a plurality of peripheral holes or perforations 50 around the perimeter of the sensor 1100, which may include holes smaller than the holes of the backplate 30, e.g., as described above with respect to Figures 9 to 10 .

[0058] Similar to the above-described rectangular sensors, respective electrodes may be formed in the membrane 10 and the backplate 30, and these electrodes may at least partially overlap in a sensing region 110 that forms a variable sensing capacitor. In the example shown in Figure 11 , the sensing region 110 forms an annulus, i.e., a ring or "donut" shape. However, it should be noted that the sensing region 110 may be any suitable shape having a removed central portion. Additionally, similar to the above-described rectangular sensors, the sensing region 110 may be connected to a sensing circuit via a connector 25.

[0059] Turning toFigure 12 , shows another exemplary circular MEMS sensor 1200, which includes a membrane 10 and a backplate 30. The backplate 30 has peripheral holes 50 in a manner similar to the above-described sensor 1100. In addition, as Figure 12 shown, the sensor 1200 has an annular sensing region 110, which can be formed via the membrane and the backplate electrodes in a manner similar to the sensor 1100. The sensing region 110 can be electrically coupled to the sensing circuit via a connector 25 in a manner similar to Figure 11 the sensor 1100 in

[0060] Different from the Figure 11 shown sensor 1100, the sensor 1200 has a multi-region backplate 30, which includes a first region 32 with a first hole density located around the boundary of the sensor 1200 and on either side of the sensing region 110. The backplate 30 also has a second region 34 with a second hole density, and the second hole density is greater than the first hole density of the first region 32, for example, as defined based on the total hole area relative to the area of each region. The second region 34 of the backplate 30 can have the same shape as the sensor 1200, such as circular (or oval), and can be positioned near the center of the membrane 10. The first region 32 of the backplate 30 can occupy the remaining part of the backplate 30, for example, forming a ring around the second region 34 of the backplate 30.

[0061] Figure 13 shows an additional example circular MEMS sensor 1300 that can be configured according to various embodiments of the present disclosure. Figure 13 The sensor 1300 shown in Figures 11 to 12 includes a membrane 10 and a backplate 30. The backplate 30 can have the same shape as the sensor 1300 and is generally located within the sensor 1300 in a manner similar to that described above with respect to Figure 13 Although the backplate 30 shown in

[0062] Figure 13 does not include peripheral holes 50, it should be noted that the peripheral holes 50 can be added to the backplate 30 in a manner similar to the above. Figure 13 shown, in the first region 32 of the membrane 10 and the backplate 30, substantially circular (or oval) electrodes are formed at or near the center of the membrane 10, thereby forming a circular (or oval) sensing region 110 at and / or near the center of the sensor 1300. The sensing region 110 can be in a manner similar toFigure 11 The sensor 1100 therein is electrically coupled to the sensing circuit via the connector 25 in a similar manner.

[0063] Figure 14 Another exemplary circular MEMS sensor 1400 including a membrane 10 and a backplate 30 is shown. The backplate 30 can be positioned and / or configured in a manner similar to that of the sensors described above with respect to Figures 11 to 13 Here, the backplate 30 includes three regions, namely a first region 32 of low-density holes forming a ring around the center point of the sensor 1300 and two second regions 34 of high-density holes in the remaining part of the backplate 30. More specifically, the second region 34 includes one region positioned in the area adjacent to the center of the membrane 10 of the backplate 30 and another region positioned in the area defined by the first region 32 of the backplate 30 and the periphery of the membrane 10. As Figure 14 Further shown, a backplate electrode can be formed in the first region 32 of the backplate 30. The backplate electrode combines with the membrane electrode formed in the corresponding part of the membrane 10 to form an annular sensing region 110. The annular sensing region 110 can be similar in shape and / or size to the sensing region described above with respect to Figures 11 to 12 The sensing region 110 can also be electrically coupled to the sensing circuit via the connector 25 in a manner similar to that described above with respect to Figures 11 to 12 the described manner.

[0064] Next, referring to Figure 15 , a simplified top perspective view of a MEMS acoustic sensor 1500 configured according to various embodiments of the present disclosure and including a shielding electrode 60 is provided. Although Figure 15 the shape of the sensor 1500 shown in Figure 15 is circular, it should be noted that similar techniques can be used for sensors of any suitable shape, such as oval, square or rectangular, hexagonal, octagonal and / or any other shape. As Figure 11 shown, the sensor 1500 includes a membrane 10 and a backplate 30, which is a single-region backplate with a plurality of holes (a plurality of perforations) of uniform density and can be configured in a manner similar to that described above with respect to Figure 15 Although the sensor 1500 is not shown in

[0065] as including the peripheral holes 50, it should be noted that the peripheral holes 50 can be added to the sensor 1500 as generally described above. Figure 15 As Figure 15In the example shown, there are two shielding electrodes 60, including a generally circular (or oval) shielding electrode at or near the center of the membrane 10 and a partial annular shielding electrode located around the periphery of the sensor 1500.

[0066] In one embodiment, the shielding electrode 60 can be formed in one of the membrane 10 or the backplate 30 and electrically coupled to the other of the membrane 10 and the backplate 30 through the connector 24. Thus, for example, the shielding electrode 60 formed in a part of the membrane 10 can be electrically coupled to the backplate 30, and the shielding electrode 60 formed in a part of the backplate 30 can be electrically coupled to the membrane 10. This can result in the formation of a shielding capacitor at the area of the sensor 1300 corresponding to the shielding electrode 60 to reduce the deflection amount of the membrane 10 away from the sensing region 110. As Figure 15 shown, a part of the sensing region 110 and / or the outer shielding electrode 60 of the sensor 1500 can be removed and / or otherwise omitted to facilitate these electrical connections. In one embodiment, the shielding electrode 60 can be electrically coupled via the connector 24 such that the voltage between the shielding electrode and the membrane electrode or the backplate electrode is less than about 10% of the bias voltage associated with the sensor 1500 to reduce the electrostatic force acting on the membrane 10, thereby reducing the deflection of the membrane 10.

[0067] Although Figure 15 two shielding electrodes 60 are shown, it should be noted that, for example Figure 15 the example sensor shown can have only one of the shown shielding electrodes 60 and / or have one or more other shielding electrodes in a configuration Figure 15 not shown.

[0068] Referring Figures 16 to 17 to, various views of an example MEMS microphone membrane 10 and backplate 30 that can be configured according to various embodiments of the present disclosure are shown. Figure 16 is a top perspective view showing the backplate 30 and the membrane 10. The backplate 30 has high-density and low-density perforated regions, and the membrane 10 can be placed above the backplate 30, for example, in an off-page direction relative to Figure 16 . In one embodiment, the membrane 10 can be anchored and / or clamped on the top and bottom sides of the Figure 16 shown sensor assembly, and the backplate 30 can be attached to the left and right sides of the assembly, for example. As Figure 16 additionally shown, the groove 70 can be cut and / or otherwise formed into the side of the membrane 10 to separate the membrane portion 10 from the edge region.

[0069] Figure 17An isometric view of another example MEMS sensor with a backplane 30 is shown. The backplane 30 has two different regions separated from each other by large holes or openings. The membrane 10 is located above the backplane 30, for example, in a manner similar to the Figure 16 membrane 10 shown therein. Figure 17 The membrane 10 shown in Figure 16 also includes corresponding trenches 70, which can be formed in the sides of the membrane 10 in a manner similar to that described above with respect to Figure 16 Although an example of a membrane 10 with substantially linear trenches 70 is shown, Figure 17 an example with curved trenches 70 is shown.

[0070] In this specification, the reference to "one embodiment" or "an embodiment" means that the specific features, structures, or characteristics described in connection with the embodiment are included in at least one implementation. Thus, the phrases "in one embodiment" or "in an embodiment" that appear throughout the specification do not necessarily refer to the same embodiment. Additionally, in one or more embodiments, the specific features, structures, or characteristics may be combined in any suitable manner.

[0071] Furthermore, in this specification, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or the context clearly indicates otherwise, "X uses A or B" is intended to mean any natural inclusive arrangement. That is, X uses A; X uses B; or X uses both A and B, in which case "X uses A or B" holds in any of the above situations. Additionally, the articles "a" and "an" used in this specification and the drawings should generally be construed to mean "one or more", unless otherwise specified or the context clearly indicates otherwise, and are in the singular form.

[0072] Moreover, the terms "example" and "for example" are used herein to denote being used as an instance or illustration. Any embodiment or design described as an "example" or mentioned in conjunction with an "for example" clause is not necessarily to be construed as being better or more advantageous than other embodiments or configurations. Instead, the use of terms such as "example" or "for example" is to present concepts in a specific manner. Unless the context clearly indicates otherwise, the terms "first", "second", "third", etc. used in the claims and the specification are for clarity only and do not necessarily indicate or imply any chronological order.

[0073] The foregoing description includes examples of one or more embodiments of the present disclosure. Of course, for purposes of describing these examples, it is not possible to describe every conceivable combination of components or methods, and it will be appreciated that many further combinations and permutations of these embodiments are possible. Accordingly, the embodiments disclosed and / or claimed herein are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the implementations and the appended claims. Further, with respect to the term "comprising" used in the implementations or the appended claims, such term is intended to be inclusive in a manner similar to the term "including" in that "including" is interpreted as "comprising" when used as a transitional word in a claim. The following clauses describe various non-limiting aspects.

[0074] Clause 1: A microelectromechanical system (MEMS) sensor, comprising: a membrane; membrane electrodes formed in a portion of the membrane; and a backplate positioned parallel to the membrane and separated by a gap, the backplate comprising: a first region of the backplate, wherein: a first density of a plurality of first through-holes are formed in the first region of the backplate, backplate electrodes are formed in a portion of the first region of the backplate, and a portion of the membrane electrodes overlaps a portion of the backplate electrodes in a sensing region forming a sensing capacitor configured to sense movement of the membrane in response to acoustic pressure; and a second region of the backplate, wherein a second density of a plurality of second through-holes are formed in the second region, and wherein the second density is greater than the first density.

[0075] Clause 2: The MEMS sensor according to any of the preceding clauses, wherein the backplate electrodes comprise a plurality of electrodes.

[0076] Clause 3: The MEMS sensor according to any of the preceding clauses, wherein the membrane electrodes comprise a plurality of electrodes.

[0077] Clause 4: The MEMS sensor according to any of the preceding clauses, wherein the backplate electrodes comprise a portion of the second region of the backplate.

[0078] Clause 5: The MEMS sensor according to any of the preceding clauses, wherein the backplate electrodes are first backplate electrodes, and wherein the MEMS sensor further comprises: second backplate electrodes formed in the first region of the backplate, wherein the second backplate is electrically coupled to the membrane electrodes.

[0079] Clause 6: The MEMS sensor according to any of the preceding clauses, wherein the membrane electrodes are first membrane electrodes, and wherein the MEMS sensor further comprises: second membrane electrodes formed in the first region of the backplate, wherein the second membrane electrodes are electrically coupled to the backplate electrodes.

[0080] Clause 7: The MEMS sensor according to any one of the preceding clauses, wherein the second region of the backplane is located in an area where the backplane is offset from the center of the membrane.

[0081] Clause 8: The MEMS sensor according to any one of the preceding clauses, wherein the second region of the backplane is located in an area where the backplane overlaps with the center of the membrane.

[0082] Clause 9: The MEMS sensor according to any one of the preceding clauses, wherein the backplane further includes a plurality of first regions, the plurality of first regions includes the first region, and wherein, several corresponding first regions of the plurality of first regions include several backplane electrodes, the several backplane electrodes include the backplane electrode.

[0083] Clause 10: The MEMS sensor according to any one of the preceding clauses, wherein the membrane is rectangular in shape.

[0084] Clause 11: The MEMS sensor according to any one of the preceding clauses, wherein the membrane is anchored or clamped along both sides of the membrane.

[0085] Clause 12: The MEMS sensor according to any one of the preceding clauses, wherein the second region includes a single opening.

[0086] Clause 13: The MEMS sensor according to any one of the preceding clauses, wherein the several second perforations are larger than the several first perforations.

[0087] Clause 14: The MEMS sensor according to any one of the preceding clauses, wherein the first region of the backplane is located in an area where the backplane is positioned adjacent to the center of the membrane.

[0088] Clause 15: The MEMS sensor according to any one of the preceding clauses, wherein the second region of the backplane is located in an area where the backplane is positioned adjacent to at least an edge of the membrane.

[0089] Clause 16: The MEMS sensor according to any one of the preceding clauses, wherein the membrane is circular or oval.

[0090] Clause 17: The MEMS sensor according to any one of the preceding clauses, wherein the first region of the backplane has the same shape as the shape of the membrane.

[0091] Clause 18: The MEMS sensor according to any of the preceding clauses, wherein the second region of the backplate has the same shape as the shape of the membrane and is positioned in a first area that is centered-offset with respect to the membrane on the backplate, wherein the first region of the backplate forms a ring surrounding the second region of the backplate, and wherein the backplate further includes: a third region in which a plurality of second perforations of the second density are formed, and the third region is positioned in a second area defined by the first region of the backplate and the periphery of the membrane.

[0092] Clause 19: The MEMS sensor according to any of the preceding clauses, wherein the first density is the first area of the plurality of first perforations divided by the second area of the first region.

[0093] Clause 20: The MEMS sensor according to any of the preceding clauses, wherein the density of the first perforations outside the sensing region is greater than the density of the second perforations inside the sensing region.

[0094] Clause 21: The MEMS sensor according to any of the preceding clauses, wherein: a second part of the membrane electrode overlaps with a second part of the backplate electrode in a routing region that forms a routing capacitor, wherein the routing region provides an electrical connection to the sensing capacitor, and a first capacitance of the routing capacitor in response to a first change in the sound pressure is less than a second capacitance of the sensing capacitor in response to a second change in the sound pressure.

[0095] Clause 22: The MEMS sensor according to any of the preceding clauses, further including a third region in the backplate or the membrane, wherein the third region excludes the sensing region.

[0096] In various aspects, any combination or combinations of Clauses 1-22 can be implemented.

[0097] Clause 23: A microelectromechanical system (MEMS) sensor, comprising: a membrane; a membrane electrode formed in a part of the membrane; a backplate positioned parallel to the membrane and separated from the membrane by a gap; a backplate electrode formed in a part of the backplate, wherein the membrane electrode at least partially overlaps with the backplate electrode in a sensing region that forms a sensing capacitor; and a sensing circuit coupled to the sensing capacitor and configured to sense the movement of the membrane in response to a sound pressure, wherein the sensing region is located at a position away from the point of maximum movement of the membrane in response to the sound pressure.

[0098] Clause 24: The MEMS sensor according to any of the preceding clauses, wherein the sensing region includes a plurality of sensing regions, and wherein the plurality of sensing regions are adjacent to corresponding regions of the membrane that exclude the point of maximum movement.

[0099] Clause 25: The MEMS sensor according to any one of the preceding clauses, wherein each of the plurality of sensing regions is symmetrically offset relative to the center of the membrane.

[0100] Clause 26: The MEMS sensor according to any one of the preceding clauses, wherein the membrane is anchored to a first opposite side of the housing, and wherein the back plate is anchored to at least a second opposite side of the housing, the first opposite side being orthogonal to the second opposite side.

[0101] Clause 27: The MEMS sensor according to any one of the preceding clauses, wherein the housing is circular, oval, rectangular, hexagonal, or octagonal.

[0102] Clause 28: The MEMS sensor according to any one of the preceding clauses, wherein the back plate includes: a plurality of peripheral holes along the periphery of the back plate; and a plurality of back plate holes located at the center of the back plate, wherein the plurality of back plate holes are larger than the plurality of peripheral holes.

[0103] Clause 29: The MEMS sensor according to any one of the preceding clauses, wherein the membrane is clamped at corresponding edges of the membrane.

[0104] Clause 30: The MEMS sensor according to any one of the preceding clauses, wherein the shape of the sensing region is annular.

[0105] Clause 31: The MEMS sensor according to any one of the preceding clauses, further comprising: a shielding capacitor disposed in a region of the MEMS sensor excluding the sensing region, the shielding capacitor including a shielding electrode formed in a part of the membrane or the back plate.

[0106] Clause 32: The MEMS sensor according to any one of the preceding clauses, wherein the shielding electrode is formed in the membrane and is electrically coupled to the back plate electrode.

[0107] Clause 33: The MEMS sensor according to any one of the preceding clauses, wherein the shielding electrode is formed in the back plate and is electrically coupled to the membrane electrode.

[0108] Clause 34: The MEMS sensor according to any one of the preceding clauses, wherein the voltage between the shielding electrode and the membrane electrode is less than 10% of the bias voltage.

[0109] In various aspects, any combination or combinations of Clauses 23 - 34 can be implemented.

[0110] Clause 35: A microelectromechanical (MEMS) acoustic sensor, comprising: a membrane; a membrane electrode formed in a portion of the membrane; and a backplate positioned parallel to the membrane and separated by a gap, the backplate comprising: a first region of the backplate in which a plurality of first perforations having a first density are formed; a second region of the backplate in which a plurality of second perforations having a second density are formed, wherein the second density is greater than the first density; and a backplate electrode formed in a portion of the backplate, wherein a portion of the membrane electrode overlaps a portion of the backplate electrode in a sensing region forming a sensing capacitor configured to sense movement of the membrane in response to an acoustic pressure, wherein the first region of the backplate surrounds a point of maximum movement of the membrane in response to the acoustic pressure; and wherein the second region of the backplate is located away from the point of maximum movement of the membrane in response to the acoustic pressure.

[0111] Clause 36: The MEMS sensor according to any of the preceding clauses, wherein the backplate further comprises: a plurality of peripheral perforations along a periphery of the backplate, wherein a density of the plurality of peripheral perforations is lower than a density of the plurality of first perforations and the plurality of second perforations.

[0112] Clause 37: The MEMS sensor according to any of the preceding clauses, further comprising: a second portion of the membrane electrode overlapping a second portion of the backplate electrode in a routing region forming a routing capacitor, wherein the routing region provides an electrical connection to the sensing capacitor, wherein a first capacitance of the routing capacitor in response to a first change in the acoustic pressure is less than a second capacitance of the sensing capacitor in response to a second change in the acoustic pressure.

[0113] Clause 38: The MEMS sensor according to any of the preceding clauses, further comprising: a shielding capacitor disposed in a region of the MEMS sensor excluding the sensing region, the shielding capacitor comprising a shielding electrode formed in a portion of the membrane or the backplate.

[0114] Clause 39: The MEMS sensor according to any of the preceding clauses, wherein the shielding capacitor is disposed in a region of the MEMS sensor excluding the routing region.

[0115] Clause 40: The MEMS sensor according to any of the preceding clauses, wherein the sensing region excludes a periphery of the backplate.

[0116] In various aspects, any combination or permutation of Clauses 35 - 40 can be implemented.

[0117] In various aspects, any combination or permutation of Clauses 1 - 40 can be implemented.

Claims

1. A microelectromechanical system (MEMS) sensor, comprising: A membrane; A membrane electrode formed in a part of the membrane; And A backplate positioned parallel to the membrane and separated by a gap, the backplate comprising: A first region of the backplate, wherein: A plurality of first perforations with a first density are formed in the first region of the backplate, A backplate electrode is formed in a part of the first region of the backplate, and A part of the membrane electrode overlaps with a part of the backplate electrode in a sensing region forming a sensing capacitor, the sensing capacitor being configured to sense the movement of the membrane in response to sound pressure; and A second region of the backplate, in which a plurality of second perforations with a second density are formed, wherein the second density is greater than the first density.

2. The MEMS sensor according to claim 1, wherein The backplate electrode comprises a plurality of electrodes.

3. The MEMS sensor according to claim 1, wherein, The membrane electrode comprises a plurality of electrodes.

4. The MEMS sensor according to claim 1, wherein, The backplate electrode comprises a part of the second region of the backplate.

5. The MEMS sensor according to claim 1, wherein, The backplate electrode is a first backplate electrode, and wherein the MEMS sensor further comprises: A second backplate electrode formed in the first region of the backplate, wherein the second backplate is electrically coupled to the membrane electrode.

6. The MEMS sensor according to claim 1, wherein, The membrane electrode is a first membrane electrode, and wherein the MEMS sensor further comprises: A second membrane electrode formed in the first region of the backplate, wherein the second membrane electrode is electrically coupled to the backplate electrode.

7. The MEMS sensor according to claim 1, wherein, The second region of the backplate is positioned in an area where the center of the backplate is offset relative to the membrane.

8. The MEMS sensor according to claim 1, wherein, The second region of the backplate is positioned in an area where the center of the backplate overlaps with the center of the membrane.

9. The MEMS sensor according to claim 1, wherein, The backplate further comprises a plurality of first regions, the plurality of first regions including the first region, and wherein a plurality of corresponding first regions of the plurality of first regions include a plurality of backplate electrodes, the plurality of backplate electrodes including the backplate electrode.

10. The MEMS sensor according to claim 1, wherein, The membrane is rectangular in shape.

11. The MEMS sensor according to claim 10, wherein, The membrane is anchored or clamped along both sides of the membrane.

12. The MEMS sensor according to claim 1, wherein, The second region includes a single opening.

13. The MEMS sensor according to claim 1, wherein, The plurality of second perforations are larger than the plurality of first perforations.

14. The MEMS sensor according to claim 1, wherein, The first region of the backplate is positioned in an area where the backplate is positioned adjacent to the center of the membrane.

15. The MEMS sensor according to claim 1, wherein, The second region of the backplate is positioned in an area where the backplate is positioned adjacent to at least an edge of the membrane.

16. The MEMS sensor according to claim 1, wherein, The membrane is circular or oval.

17. The MEMS sensor according to claim 1, wherein, The first region of the backplate has the same shape as the shape of the membrane.

18. The MEMS sensor according to claim 1, wherein, The second region of the backplate has the same shape as the shape of the membrane, and is positioned in a first area where the center of the backplate is offset relative to the membrane, wherein the first region of the backplate forms a ring surrounding the second region of the backplate, and wherein the backplate further comprises: A third region, in which the plurality of second perforations with the second density are formed, the third region being positioned in a second area defined by the first region of the backplate and the periphery of the membrane.

19. The MEMS sensor according to claim 1, wherein, The first density is the first area of the plurality of first perforations divided by the second area of the first region.

20. The MEMS sensor according to claim 1, wherein, The density of the first perforations outside the sensing region is greater than the density of the second perforations inside the sensing region.

21. The MEMS sensor according to claim 1, wherein: A second part of the membrane electrode overlaps with a second part of the backplate electrode in a routing region forming a routing capacitor, wherein the routing region provides an electrical connection to the sensing capacitor, and The first capacitance of the routing capacitor responds less to the first change in the sound pressure than the second capacitance of the sensing capacitor responds to the second change in the sound pressure.

22. The MEMS sensor according to claim 1, further comprising a third region in the backplane or the film, wherein, The third region excludes the sensing region.

23. A microelectromechanical system (MEMS) sensor, comprising: A membrane; A membrane electrode formed in a part of the membrane; A backplate positioned parallel to the membrane and separated from the membrane by a gap; A backplate electrode formed in a part of the backplate, wherein the membrane electrode at least partially overlaps the backplate electrode in a sensing region forming a sensing capacitor; and A sensing circuit coupled to the sensing capacitor and configured to sense the movement of the membrane in response to sound pressure, wherein the sensing region is located at a position away from the point of maximum movement of the membrane in response to the sound pressure.

24. The MEMS sensor according to claim 23, wherein, The sensing region includes a plurality of sensing regions, and wherein the plurality of sensing regions are adjacent to corresponding regions of the membrane excluding the point of maximum movement.

25. The MEMS sensor according to claim 24, wherein, Each of the plurality of sensing regions is symmetrically offset with respect to the center of the membrane.

26. The MEMS sensor according to claim 23, wherein, The membrane is anchored to a first opposite side of the housing, and wherein the backplate is anchored to at least a second opposite side of the housing, the first opposite side being orthogonal to the second opposite side.

27. The MEMS sensor according to claim 26, wherein, The housing is circular, elliptical, rectangular, hexagonal, or octagonal.

28. The MEMS sensor according to claim 23, wherein, The backplate includes: A plurality of peripheral holes along the periphery of the backplate; and A plurality of backplate holes located at the center of the backplate, wherein the plurality of backplate holes are larger than the plurality of peripheral holes.

29. The MEMS sensor according to claim 23, wherein, The membrane is clamped at corresponding edges of the membrane.

30. The MEMS sensor according to claim 23, wherein, The shape of the sensing region is annular.

31. The MEMS sensor according to claim 23, further comprising: A shielding capacitor disposed in a region of the MEMS sensor excluding the sensing region, the shielding capacitor including a shielding electrode formed in a part of the membrane or the backplate.

32. The MEMS sensor according to claim 31, wherein, The shielding electrode is formed in the membrane and electrically coupled to the backplate electrode.

33. The MEMS sensor according to claim 31, wherein, The shielding electrode is formed in the backplate and electrically coupled to the membrane electrode.

34. The MEMS sensor according to claim 31, wherein, The voltage between the shielding electrode and the membrane electrode is less than 10% of the bias voltage.

35. A microelectromechanical (MEMS) acoustic sensor, comprising: A membrane; A membrane electrode formed in a part of the membrane; And A backplate positioned parallel to the membrane and separated by a gap, the backplate including: A first region of the backplate in which a plurality of first perforations having a first density are formed; A second region of the backplate in which a plurality of second perforations having a second density are formed, wherein the second density is greater than the first density; and A backplate electrode formed in a part of the backplate, Wherein a part of the membrane electrode overlaps a part of the backplate electrode in a sensing region forming a sensing capacitor configured to sense the movement of the membrane in response to sound pressure, Wherein the first region of the backplate surrounds the point of maximum movement of the membrane in response to the sound pressure; and Wherein the second region of the backplate is located at a position away from the point of maximum movement of the membrane in response to the sound pressure.

36. The MEMS sensor according to claim 35, wherein, The backplate further includes: A plurality of peripheral perforations along the periphery of the backplate, wherein the density of the plurality of peripheral perforations is lower than that of the plurality of first perforations and the plurality of second perforations.

37. The MEMS sensor according to claim 35, further comprising: A second portion of the membrane electrode overlaps a second portion of the backplane electrode in a routing region that forms a routing capacitor, wherein the routing region provides an electrical connection to the sensing capacitor. A first capacitance of the routing capacitor in response to a first change in the sound pressure is less than a second capacitance of the sensing capacitor in response to a second change in the sound pressure.

38. The MEMS sensor according to claim 37, further comprising: A shielding capacitor disposed in a region of the MEMS sensor excluding the sensing region, the shielding capacitor including a shielding electrode formed in a portion of the membrane or the backplane.

39. The MEMS sensor according to claim 38, wherein, The shielding capacitor is disposed in a region of the MEMS sensor excluding the routing region.

40. The MEMS sensor according to claim 35, wherein, The sensing region excludes a periphery of the backplane.

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